1. Field of the Invention
The invention relates in general to a method of changing a polyphony number, and more particularly to a method of dynamically determining a maximum polyphony number according to an operation mode of the electronic device, and smoothly changing a polyphony number according the switch of the operation modes of the electronic device.
2. Description of the Related Art
Electronic devices have become indispensable in the daily life of the modern human beings. With the electrical communication devices, such as mobile telephones and personal digital assistants (PDAs), conforming with the communication protocol specifications including the globe system for mobile communications (GSM), the circuit switch data (CSD) and the general packet radio service (GPRS), people can communicate with others at any place.
In addition, with the newly developed software music synthesizer technology, the electronic device can play music that has been upgraded from the monophonic ring-tone to the 4-polyphonic ring-tone, the 8-polyphonic ring-tone, or even the 16-polyphonic ring-tone. Generally, music synthesis highly depends on the computing power of the processor in the electronic device. The electronic device with the stronger computing power can synthesize more polyphony, meaning that more notes can be simultaneously played.
FIG. 1 is a schematic illustration showing a maximum polyphony number of a conventional electronic device. As shown in FIG. 1, it is assumed that the total computing power of the electronic device 10 having a software music synthesizer is X, and the maximum computing power required for only regular operations, which function without the software music synthesizer, is Y. Hence, (X−Y) is the computing power available for running the software music synthesizer. Assuming that M is a constant computing power required to synthesize a tone, the maximum polyphony number would be the maximum integer less than the number of (X−Y)/M. For example, the maximum positive integer is 6, as shown in FIG. 1. As a result, the electronic device 10 has the maximum polyphony number of 6.
The electronic device generally has multiple operation modes, such as an idle mode, a standby mode and an application mode. And, the computing power Y will be different in different mode. However, conventionally, the maximum polyphony number of the electronic device is held constant in any operation mode.